A review is presented of 233 patients who were surgically treated for bronchial carcinoma during a five-year period. The survival time was determined in relation to operative procedure and to cell type and anatomic extent of the tumours. Staging according to the TNM classification gave five-year survival rates of 51.6% in Stage I, 12.0% in Stage II and 8.4% in Stages III-IV. Among the Stage I cases, tumours classified as T1N0M0 were associated with longer survival than were T1N1M0 or T2N0M0 tumours. It is concluded that the stage of the disease as defined by TNM classification should be regarded as the most important prognostic factor.